httpd-overrides

Neutron HTTPD Configuration Overrides

The neutron-operator provides mechanisms to customize the Apache HTTPD server configuration through the use of custom configuration files. This feature leverages the ExtraMounts functionality to mount custom HTTPD configuration files into the Neutron deployment.

How It Works

1. Custom Configuration Files: Create HTTPD configuration files with your custom settings
2. ConfigMap: Create ConfigMaps from files containing the overrides
3. OpenStackControlPlane Patch: Patch the control plane to mount the generated ConfigMap into Neutron containers. The HTTPD configuration automatically includes files mounted to /etc/httpd/conf_custom/*.conf

Step 1: Create Custom HTTPD Configuration

Create your custom HTTPD configuration file(s). As a best practice the filename could start with the httpd_custom_ prefix, but all *.conf files mounted to /etc/httpd/conf_custom/ are automatically included by the IncludeOptional directive in the base httpd configuration.

Example (httpd_custom_connection.conf):

# Custom connection settings for Neutron
MaxKeepAliveRequests 200
KeepAliveTimeout 15

Step 2. Create a ConfigMap

Create a Kubernetes ConfigMap containing your custom configuration files:

oc create configmap httpd-overrides --from-file=httpd_custom_connection.conf

It is possible to add multiple configuration files containing dedicated configuration directives:

oc create configmap httpd-overrides \
  --from-file=httpd_custom_connection.conf \
  --from-file=httpd_custom_security.conf \
  --from-file=httpd_custom_logging.conf

The following example is based on a single customization file and demonstrates how to set custom MaxKeepAliveRequests and KeepAliveTimeout parameters.

Step 3: Configure ExtraMounts in the OpenStackControlPlane

Update your OpenStackControlPlane resource to include the custom HTTPD configuration files using extraMounts. The simplest approach is to mount the entire ConfigMap to the target /etc/httpd/conf_custom mount point:

apiVersion: core.openstack.org/v1beta1
kind: OpenStackControlPlane
metadata:
  name: openstack
spec:
  neutron:
    template:
      extraMounts:
      - extraVol:
        - extraVolType: httpd-overrides
          mounts:
          - mountPath: /etc/httpd/conf_custom
            name: httpd-overrides
            readOnly: true
          volumes:
          - configMap:
              name: httpd-overrides
            name: httpd-overrides

Common Use Cases

• Connection Tuning: Adjust keep-alive settings, connection limits, etc.
• Security Headers: Add custom security headers or configurations
• Logging: Customize Apache logging configuration
• Performance Tuning: Adjust worker processes, thread limits, etc.

Verification

After deploying your custom HTTPD configuration, you can verify that the settings have been properly applied:

1. Find the Neutron Pod

First, identify the running Neutron pod:

$ oc get pods -l service=neutron

2. Verify Configuration Loading

Connect to the Neutron Pod and check that your custom configuration has been loaded:

# Replace <neutron-pod-name> with the actual pod name from step 1
oc rsh -c neutron-httpd <neutron-pod-name>
# Inside the pod, dump the HTTPD configuration and check for your custom settings
httpd -D DUMP_CONFIG

3. Additional Verification Commands

You can also verify other aspects of the configuration:

# Check all loaded configuration files
$ httpd -D DUMP_INCLUDES